Measles can be a life-threatening infection in immunocompromised patients, especially after allogeneic hematopoietic cell transplantation (HCT) because of the corresponding loss of immunity. However, measles vaccines are live-attenuated, which is why measles vaccinations are recommended only in seronegative HCT recipients and in specific conditions. However, little data exist on the rates of seroprotection to measles with the current conditioning regimens and in long-term follow-up. The objectives of this study were to assess measles immunity before considering vaccination in a cohort of allogeneic HCT long-term survivors and to identify the factors associated with seropositivity/seroprotection. One hundred and twenty-six patients who underwent transplantation between 1 and 39 years earlier (median, 9 years) were assessed for measles immunity. Measles IgG titers were determined with an automated chemiluminescent immunoassay. Seropositivity/seroprotection was defined by an IgG titer >16.5 UA/mL. Patients underwent transplantation with a reduced-intensity conditioning (RIC) or nonmyeloablative (NMA) conditioning in 46% of cases, mainly for acute leukemia (61%). Seventy-eight of the 126 patients (62%) were seropositive/seroprotected for measles. Among the seropositive patients, the patients who had been vaccinated before transplantation had a lower median IgG titer compared with those who had not (48 UA/mL versus 116 UA/mL). Myeloproliferative disorder, RIC or NMA conditioning, and absence of acute grade ≥II graft-versus-host disease were associated with seropositivity/seroprotection. With a 62% rate of seropositivity/seroprotection for measles at a median of 9 years after transplantation, our findings strongly support a systematic assessment of anti-measles antibody titers to avoid unnecessary vaccination in seroprotected patients.

中文翻译：

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同种异体造血细胞移植后对麻疹的长期免疫：再次接种前与血清保护相关的因素。

在免疫功能低下的患者中，麻疹可能是威胁生命的感染，尤其是在异体造血细胞移植（HCT）后，由于相应的免疫力下降。但是，麻疹疫苗是减毒活疫苗，这就是为什么仅在血清阴性的HCT接受者和特定情况下才建议进行麻疹疫苗接种的原因。但是，关于目前的调理方案和长期随访中关于麻疹的血清保护率的资料很少。这项研究的目的是在考虑接受同种异体HCT长期幸存者队列中的疫苗接种之前评估麻疹免疫力，并确定与血清阳性/血清保护相关的因素。评估了126名在1至39年前（中位数为9岁）接受移植的患者的麻疹免疫力。用自动化学发光免疫测定法测定麻疹IgG效价。血清抗体阳性/血清保护定义为IgG滴度> 16.5 UA / mL。在46％的病例中，患者接受了降低强度调节（RIC）或非清髓性（NMA）调节的移植，主要针对急性白血病（61％）。126名患者中有78名（62％）呈麻疹血清阳性/血清保护。在血清反应阳性患者中，移植前接受过疫苗接种的患者的IgG滴度中位数低于未接受血清的患者（48 UA / mL对116 UA / mL）。骨髓增生异常，RIC或NMA调节以及急性≥II级移植物抗宿主病均与血清阳性/血清保护有关。